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Technical Proposal
For IGW
Huawei Technologies Co. Ltd.
MAY 2012
Technical Proposal for IGW
Commercial in Confidence Page 2 of 46
Table of Contents
Table of Contents .............................................................................................................................. 2
1 Huawei proposal for BIG Overview ......................................................................................... 3
1.1 Analysis of BIG IGW Requirements ............................................................................. 3
1.2 Huawei proposal for BIG .............................................................................................. 5
1.2.1 Overview of Proposed Solution ............................................................................ 5
1.2.2 Key Points of Huawei Design ............................................................................... 7
1.2.3 Scalability (IGW) ................................................................................................... 8
1.2.4 High Flexibility Solutions ....................................................................................... 8
1.2.5 System reliability ................................................................................................... 9
1.3 Datacom Solution ....................................................................................................... 17
1.3.1 Bandwidth Capacity and Link Design ................................................................. 18
1.3.2 Datacom Solution Highlights............................................................................... 19
1.4 Huawei Transmission Network Solution ..................................................................... 20
1.4.1 Solution Overview ............................................................................................... 20
1.4.2 Huawei NG-SDH Features ................................................................................. 20
1.5 Power Solution ........................................................................................................... 23
1.5.1 Dimension of Power Solution.............................................................................. 24
1.5.2 Reliability of Power Solution ............................................................................... 24
1.6 Huawei NMS Solution ................................................................................................ 24
1.6.1 Powerful Huawei Network Management ............................................................ 26
1.6.2 Abundant Northbound Interfaces for OSS Integrated Solution .......................... 26
1.7 Lawful Interception Solution ....................................................................................... 28
1.8 Inter-working Solution ................................................................................................. 30
1.8.1 Inter-working with TDM Networks ....................................................................... 30
1.8.2 Inter-working with IP Networks ........................................................................... 30
1.9 Illegal Number Blocking .............................................................................................. 31
1.9.1 The incoming call number is standard number................................................... 32
1.9.2 Illegal incoming number call rejected ................................................................. 33
2 Key Solution Highlights .......................................................................................................... 33
Reliability ................................................................................................................................... 34
Excellent Voice Quality .............................................................................................................. 36
3 Annex A. Abbreviations and Acronyms ................................................................................ 41
Technical Proposal for IGW
Commercial in Confidence Page 3 of 46
1 Huawei proposal for BIG Overview
1.1 Analysis of BIG IGW Requirements
In year 2011, based on the IGW new license released, BIG is going to apply International
Gateway (IGW) license to Bangladesh Telecommunication Regulatory Commission (BTRC).
This is inline with the long term business development and strategy of BIG to boast the revenues
and increase competitiveness. The main responsibilities of the IGW in BIG encompass the
following functions:
Routing/switching international voice calls between ICX and International operators.
Routing inter operator Short Message Service (SMS) as and when necessary
Providing Interface for Lawful Interception (LI) facilities
Providing Monitoring Facility of System for BTRC
Provision for Transferring CDRs to BTRC.
Provide bandwidth and infrastructure in favor of VSPs for international connectivity with
overseas carriers
Provide necessary capacities with ICX to terminate the calls of VSPs to ANS through ICXs.
Provide support to VSPs for building-up connectivity with overseas carriers, switching of the
incoming calls for call termination to ANS operators through ICX, monitoring of bandwidth
utilization, extraction and storage of Call Detail Record (CDR), sending CDR to National
Monitoring Center (NMC) for online and offline monitoring and analysis, storage and
analysis of Traffic Data, Log files, Call Accounting, Signaling and QoS related information
With these new business requirements, BIG is urgently in need to deploy a reliable, cost-efficient,
scalable and robust IGW Network. The deployment of the IGW is crucial to BIG business in the
future in terms of revenues and strategy. The successfulness of BIG IGW will propel BIG to be
experienced and efficient Class-4 and IGW operator, with huge revenues stream. As the largest
and top ILEC, BIG’s ultimate transformation strategy is moving towards ALL-IP Next Generation
Network (NGN).
BIG requires the vendor to supply, install, testing and commission the International Gateway
(IGW) with Core Network, Transmission, Datacom and other facilities on turn-key basis. The BIG
future network is an IP-based network which is fully compliant with ETSI and ITU-T standards.
The IGW covers one Point of Presence (PoP) in Dhaka, the Core Network, transmission,
Datacom and other facilities should be deployed and distributed in this PoP. The future target
architecture of BIG is shown in the following figure.
Technical Proposal for IGW
Commercial in Confidence Page 4 of 46
Figure 1 – BIG Target IGW Architecture
With extensive experience and deep insights in IGW deployment, Huawei has made out this
proposal based on thorough understanding of the requirements in IGW license document. The
key points of Huawei understanding of the tender document requirements are summarized as
the following.
1.1.1.1 Main Driver of IGW Deployment
1.1.1.1.1 One of the most notable drivers is to fulfill BTRC urgent and stringent requirements on
IGW with the tight timeline given.
1.1.1.1.2 Increase revenues stream and improve the bottom-line of the profitability of BIG
1.1.1.1.3 Insufficient capacity of current network architecture, including PSTN switch,
transmission, datacom and other facilities to support large IGW requirements.
1.1.1.1.4 BIG also want to deploy a Network which is reliable, scalable, cost-efficient and
future-oriented.
1.1.1.2 The Key Points of BIG IGW Requirments
1.1.1.2.1 Large capacity and able to scale with future growth
The IGW solution required by BIG is of large capacity and should be able to scale to support
higher capacity with modular expansion method. The network elements proposed for IGW
should support network expansion without any software and hardware upgrade.
1.1.1.2.2 Field-proven
Technical Proposal for IGW
Commercial in Confidence Page 5 of 46
The network elements proposed, including Core network, transmission and datacom must
be field proven. They should be commercially deployed in overseas market and running
stably for past few years.
1.1.1.2.3 Feature-rich
The BIG IGW solution should be feature-rich and support a host of features, including
software and hardware features. The IGW should support different routing, translation,
signaling analysis, statistics monitoring and traffic measurement features based on the
requirements in the tender document.
1.1.1.2.4 Low TCO
The IGW solution shall provide an advantageous OPEX savings and CAPEX in long term
perspective. The IGW solution should require a comprehensive construction of IGW with
minimum investment as BIG prefer one time investment.
1.2 Huawei proposal for BIG
1.2.1 Overview of Proposed Solution
Huawei proposes to use Softx3000, UMG8900, SE2600, OSN3500,NTP Server, NE40E-X3,
S9300, S3300, N/U2000, Eudemon 1000E to construct a world-class IGW network for BIG. It is
the best-in-breed solution in the industry as the proposed network elements are the most reliable
and feature-rich. The proposed solution is targeted to provide the most reliable, scalable and
robust platform for BIG large interconnection traffic purpose. Various advanced technologies and
techniques are embedded in the proposed solution. Huawei proposed BIG IGW solution and
interconnection is shown below.
Technical Proposal for IGW
Commercial in Confidence Page 6 of 46
Figure 2 – Proposed IGW Network Topology for BIG
The key ideas of Huawei proposed IGW solution are based on the following important network
components:
– Softswitch base on CPCI platform as the call control of the IGW.
– Media Gateway as the signaling and media adaptation gateway.
In the proposed IGW solution, all the equipments will be deployed in Dhaka, one Softx3000
process the call control and forwarding. The Media Gateway will be connected with ICX or other
TDM Networks. The Softx3000 will link to the International Operators by SIP/H.323 trunks
through I-SBC (SE2600).
Huawei NMS, N2000 will be centrally deployed in Dhaka, will manage IGW Core Network
elements, U2000 will manage the Datacom elements.
Two Gateway routers, four LAN switches and three Firewall will be installed at Dhaka IGW site
which will form the IP core for the proposed IGW system. One LAN switch will be installed at the
BTRC site to provide connectivity for the monitoring equipment. The Soft Switch and the Media
Gateway will be connected to the IP core with suitable IP interface (GE/FE). Fire walls are
provided to ensure network security.
One NTP server will be installed in the proposed IGW for keeping time synchronization. The
Billing system will be installed at the proposed IGW site for processing, generating and
Technical Proposal for IGW
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management of Bills. The mediation devices collect the raw CDRs from the switching network
elements, pre-process the raw CDRs applying the business rules and distribute them to the
appropriate devices for further process in order to generate the Bills. There will be sufficient
storage capacity and security in the billing system hardware for storing the billing data.
Appropriate monitoring devices (O & M Control Console) will be installed at BTRC for viewing
real-time traffic and call data and for saving traffic data, log files and CDR dumps. The monitoring
system to be provided is also capable of online and offline monitoring and analyzing of the CDR,
Call Accounting, Signaling, QoS and others.
Huawei has developed an end-to-end IGW solution in accordance with ETSI and ITU-T
standards. Huawei has been very actively participating in ETSI and ITU-T and other related
standards organizations and forums. The compliance to these standards allows BIG to safely
roll-out an end-to-end IGW network without any network issues. All the interface, including
bearer and signaling interfaces are designed in accordance to the international standardization.
The availability of these standard-conforming interfaces will allow BIG for a smooth
commissioning and inter-working with its existing network environment to the near future next
generation target network ensuring feature inter-working and end-to-end interoperability.
Product Entity in the
Tender
Functionality of Entity Units Sites
Softx3000 Softswitch Call Control 1 Dhaka
UMG8900 Media Gateway Media and signaling
adaptation
1 Dhaka
XPTU LI LI Interface Conversion 1 Dhaka
N2000 Core Network NMS NMS 1 Dhaka
NTP Server NTP 1 Dhaka
OSN3500 MUX 1 Dhaka
SE2600 SBC Session Border Controller 1 Dhaka
Table 1 Huawei IGW Solution Product Model
The solution based on the following dimension parameter:
1. Average Holding time (for all calls): 60 second
2. Erlang/trunk: 0.70
1.2.2 Key Points of Huawei Design
The IGW solution proposed is embedded with various advanced technologies and designs that
set BIG on par with the global IGW operators in the world. The solution is proposed after careful
study of the current network environment and application in Bangladesh as well as full
consideration of the requirements of a world-class IGW network stated in the BIG IGW tender
document, encompass NGN, transmission, datacom and SMS gateway.
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1.2.3 Scalability (IGW)
The traffic model for IGW solution:
1. Huawei propose the BIG IGW as the following traffic:
Site Name STM-1 E1 Erl/Trunk Average
Holding time (s)
Percentage of IP call
Dhaka 6 2 0.70 60 90%
Table 2 IGW Traffic Capacity
2. Capacity of whole systems:
Site Name TDM Trunks No. of CCS7 Sig IP Trunks Total BHCA Total Erl
Dhaka 11000 30 9000 600K 10K
Table 3 IGW Traffic Capacity
The total Trunks is 20K and the total BHCA reach to 600K under the 60s average holding time
and 0.70Erl/trunks.
3. MUX Capacity:
STM-16 STM-4 STM-1 FE
Dhaka 4 24 0
Table 4 MUX Traffic Capacity
1.2.4 High Flexibility Solutions
TDM&IP Dual Bearer
TDM&IP Dual Bearer solution can help the operator migrate his network from TDM based to IP
based smoothly.
The TDM&IP dual bearers are classified into inter-Softswitch dual bearers and intra-Softswitch
inter-MGW dual bearers.
The TDM/IP dual bearer service provides a basis for the seamless upgrade from TDM
networking to IP networking. The features of the service are as follows:
Inter-Softswitch dual bearer: A mixture of ISUP (TDM bearer), TUP (TDM bearer),is supported in
an office direction. When routing a call out of the office, the system can select a route based on
the preference policy of the bearer network.
Intra- Softswitch inter-MGW dual bearer: IP (mesh connection) and TDM bearers are used
between intra-softswitch MGWs. When connecting an intra- Softswitch call, the system can
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select a route based on the data configuration and the preference policy of the bearer network.
1.2.5 System reliability
1.2.5.1 Redundancy and Reliability of Hardware
Distributed Hardware Structure
The SOFTX3000 adopts the distributed hardware structure. The modular design of the functions
realizes the distributed processing. The functions of the modules are independent of each other,
and are controlled by different processors. The fault in one processor does not affect the
operation of the whole system.
Redundancy Design
The hardware of the SOFTX3000 adopts designs such as active/standby mode, load sharing
mode, and redundancy configuration, to ensure reliability of the hardware system.
The main parts in the SOFTX3000 adopt the multi-processor backup design. For
example, the SMU, FCCU, CDB, BSG/MSG, and iGWB have two processors working in
active/standby mode. In normal conditions, the active processor controls the running of
the module, and the standby processor synchronizes with the active one in real time.
When the active processor is faulty, the standby one takes over the service at once. The
standby processor takes the place of the faulty active processor to control the operation
of the system without interrupting the service.
The service modules and interface modules of the SOFTX3000 adopt load sharing mode.
That is, two or more boards share the related functions during the normal working. Once
a board becomes faulty, the other boards take over the tasks of the faulty board provided
that certain performance indexes, such as call loss, are ensured.
The IP interface of the SOFTX3000 supports physical backup, thereby ensuring reliability
of the IP routes between the SOFTX3000 and the IP bearer network.
Derating Design
This design is to lower the values of the electric stress and heat stress to the values smaller than
the rated values when the electronic components run. Through this, the following purposes can
be achieved:
Postponing degeneration of the parameters
Prolonging their service lives
Enhancing their reliability
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Maintainability Design
The maintainability design aims to meet the specified quantitative and qualitative demands on
maintainability, especially the demand on reducing maintenance time. The maintenance design
covers the following:
Product design and maintenance simplification
Reachability
Standardization and exchangeability
Modularization
Error prevention design and identifier
Testing and diagnosis technology
Human and environment factors
These are described as follows:
The boards are designed to be hot-pluggable to reduce board replacement time.
No cable is led out from the front panel, thus facilitating board removal and assembly, and
decreasing maintenance time.
When a module in the system is faulty, the maintenance terminal detects and reports the
fault.
The local maintenance MML operation terminal helps the maintenance staff to locate and
rectify faults quickly and easily.
Selection and Usage of Components
The selection and usage of components are key to ensure component reliability.
For the SOFTX3000, the component types, specifications, and suppliers are selected based on
the demands on product reliability. The focus is on component replacement and unification. The
component unification and reliability model analysis is used to reduce the number of components
used and improve system running, after the components pass the aging test. Thus, the
components are of high quality ensuring the reliability of the hardware system.
Power Reliability
To improve the reliability of the power supply system, the following techniques are employed in
the SOFTX3000:
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Distributed power supply: Two power supply systems work in the redundancy backup
mode. The systems have the protection functions against lightening, power failure, over
and under voltage, and over and under current. When the power fails, the whole system
can restart within five minutes.
The power module of the subrack adopts 2+2 backup design. When one power module is
faulty, it does not affect the operation of the system.
Overvoltage and overcurrent protection measures are applied to +5 V / -48 V power input
and external interfaces (such as E1 interfaces). These measures comply with Appendix B
of ITU-T Recommendation G.703 and relative specifications.
The UMG8900 supports 1+1 backup mode, N+1 backup mod and load-sharing mode for
hardware design, provides the high reliability hardware platform.
The bearer processing board and interface board support 1+1 and load-sharing mode.
The call control board supports 1+1 backup mode.
The main control board and clock cascading support 1+1 backup.
The UMG8900 supports backup of FE/GE ports and reliable networking with the L2/L3
LAN Switch, router and MSTP. If any peer network element fails, services are not
interrupted.
TDM SDH / SONET support 1+1 backup, N:1 backup and load-sharing mode.
1.2.5.2 Software Reliability
The SOFTX3000 ensures the software running status by taking measures, such as protection
measures, error tolerance measures, and fault monitoring measures.
Compliance with the CMM Flow
Huawei strictly follows the Capability Maturity Model (CMM) procedures throughout the
development of the SOFTX3000, from requirement analysis, system design to software test.
Code walk-through, inspection, review, unit test, system test, and other useful quality assurance
measures taken in the SOFTX3000 development improve the reliability of the software
considerably.
Protective Measures
The software of the SOFTX3000 applies a modular structure in hierarchical mode. All software
modules are developed based on a loose coupling mechanism, minimizing a faulty module's
impact on other modules. In addition, the software of the SOFTX3000 is added with functions of
Technical Proposal for IGW
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detecting, isolating, and correcting errors; in an emergency condition, the SOFTX3000 can
provide an approach for quickly locating the faults.
Fault Tolerance
To prevent impact on the system by certain software faults, the SOFTX3000 adopts the following
measures for the key software:
Scheduled detection
Real-time monitoring of tasks
Storage protection
Data check
Saving of operation logs
These measures improve the fault tolerance of the software, that is, the self-healing ability in the
case of software error.
Troubleshooting
The SOFTX3000 automatically detects and diagnoses hardware and software faults. It can
isolate, switch over, restart, or reload the faulty hardware.
Supporting Hot Patches
Sometimes the host software must be modified when the equipment is running in order to
remove system bugs, add new functions, and adhere to service requirements. The traditional
way is to stop the equipment for upgrading. This, however, affects the service processing and
communication quality. The SOFTX3000 supports installation of hot patches to the host software.
In this way, the host software can be upgraded without interrupting the services, thus improving
the communication quality.
The UMG8900 provides the distribution of software modules designed and high-reliability
software architecture to implement the highly reliable protection.
The realization of the distributed processing module designed to support the software
fault detection and isolation.
Support the overload protection feature. When the system overloads, it starts the
self-protection mechanism, shielding some traffic, and ensure secure and reliable
operation of the system.<}0{><0}
Technical Proposal for IGW
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1.2.5.3 Reliability of Charging
Hardware Reliability of Charging Gateway
In the iGWB system, key devices are redundant for backup. This ensures that services are not
interrupted when a fault occurs in the system.
Two-Node System
In the iGWB two-node system, each pair of boards work in active/standby mode. The
automatic switchover mechanism ensures system reliability and service continuity.
Redundant Disks Using RAID
The iGWB adopts the most commonly used RAID technology. It configures local disks as
RAID 1 to prevent data loss in case of a disk failure.
Dual-Network and Dual-Plane Architecture
iGWB server communicates with the SOFTX3000, SMU through the Base plane, Fabric
plane, and external network interfaces. This dual-plane architecture improves system
reliability. It is provide the following functions.
The SOFTX3000 is connected to iGWB through the primary and secondary links on the
Base plane to form two planes.
The primary and secondary boards are connected to the SMU through the Base plane
and then connected to the NMC through the SMU.
Data on disks are synchronized between the primary and secondary boards through the
Fabric plane.
The primary and secondary boards provide an independent external network interface for
connecting to the BC and uploading CDR files to the BC through FTP or SFTP. For
network isolation purpose, this network interface is only used to access the charging
network to ensure the network security.
Technical Proposal for IGW
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Figure 3 – Hierarchical Storage of the Bills
From the time a call is completed to the time the CDR information is transferred to the billing
center, there are four levels of CDR buffer against CDR data loss due to abnormal causes. The
four levels are: host CDR pool buffer, original CDR file buffer, final CDR file buffer and automatic
CDR file backup on the IGWB server.
Host CDR pool buffer: The host CDR pool stores the original CDRs.
Original CDR file buffer: After being transferred from the host CDR pool to the IGWB
Server, the original CDRs are stored first in the hard disk as the level-two buffer.
Final CDR file buffer: After processing the original CDRs, the IGWB Server saves the
final CDR data to be sent to the billing center to carry out the level-three buffer.
Automatic backup in IGWB Server: The IGWB Server adopts 1+1 backup mode. The
active server regularly backs up the CDR data in the hard disk to the standby server to
carry out the level-four buffer.
The primary and secondary boards provide an independent external network interface for
connecting to the third-party server and backing up CDR files to the third-party server
through FTP or SFTP. The network interface is independent to ensure network security.
Technical Proposal for IGW
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Software Reliability of Charging Gateway
The iGWB software adopts automatic fault detection, data security, a virtual IP address to
improve system reliability.
Automatic Fault Detection
The system automatically detects the running status of software and hardware and
submits faults if it occur. You can view the running status and faults of software and
hardware on the client.
If a hardware fault occurs in a key component or a fault is not rectified automatically, the
primary and secondary servers are switched over to ensure normal running of the
system.
If a software (such as a process) fault occurs or a fault is not rectified automatically, the
active and standby processes are automatically switched over to ensure normal running
of the system.
Data Security
The CDRs on the primary and secondary boards are synchronized in real time through
the CDR synchronization mechanism.
Local disks are set to a RAID mode to ensure security of important data such as charging
information, original CDRs, final CDRs, and status information.
System data is stored in different paths for redundancy backup. When an exception
occurs, system data is loaded and checked automatically.
To protect important data, the iGWB provides automatic backup of charging data.
Virtual IP Address
The virtual IP address technology is used to ensure normal connections between the
SOFTX3000 and the BS after the primary and secondary boards of the iGWB are switched
over.
Transmitting CDRs between the SOFTX3000 and the iGWB
The SOFTX3000 sends the CDRs to the iGWB in real time through UDP over two Base
planes.
Receiving CDRs by the primary and secondary boards of the iGWB
The iGWB uses CDR synchronization technology to synchronize CDR files on the primary
and secondary boards of the iGWB.
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Sliding Window Protocol
CDRs are transmitted between the SOFTX3000 and the iGWB through the Sliding Window
Protocol. The SOFTX3000 sends some CDRs to the iGWB. After receiving the CDRs, the
iGWBchecks and filters the CDRs and then stores the CDRs in the window. After the CDR
data is written into the hard disk completely, the iGWB responds to the SOFTX3000. Then
the SOFTX3000 continues to send new CDRs. To ensure transmission efficiency, the
iGWB can receive and check new CDRs while storing CDR data.
The key data about the sliding window status in the iGWB is written into the hard disk in
time. When the iGWB is restarted or the primary and secondary servers are switched over,
no CDR is lost or duplicate during transmission.
CDR Processing Reliability
Three modules are involved in the CDR processing from receiving CDRs to generating final
CDRs. The iGWB creates a reliable CDR processing task between the three modules.
CDRs are processed in the unit of the package. After original CDRs are stored successfully,
the information about CDR packages is also stored in the hard disk. After original CDRs are
processed and stored as final CDRs, the package numbers are also stored. When the
iGWB is restarted, the iGWB can calculate the package number of the original CDRs that
are not processed based on the package numbers of final CDRs. Then the iGWB continues
to process the remaining original CDRs.
CDR Distribution
When CDR files are distributed in PULL mode, the billing center fetches CDRs
from the iGWB. The iGWB provides the FTP or SFTP user name and password to
the billing center and opens the read and write authorities of the directory where
the second copy of final CDRs is stored.
When CDR files are distributed in PUSH mode, the iGWB sends CDRs to the
billing center. The billing center provides the FTP or SFTP user name and
password to the iGWB and opens the directory where the final CDRs are stored.
CDR Backup
CDR backup further ensures CDR reliability. The iGWB automatically backs up CDR files
on other storage devices through the LAN or WAN to improve data security.
1.2.5.4 Data Reliability
The SOFTX3000 provides the following data protection mechanisms:
The SOFTX3000 supports a synchronous data backup mechanism between the active
and standby modules in real time. Whenever an active module is down, the standby
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module is automatically switched to be the active one. All programs and data on the
module are immediately brought into effect.
The SOFTX3000 supports the backup of data from the database of the active processor
to a flash memory. This enables quick restart of the active processor after data is
obtained from the flash memory.
The SOFTX3000 supports the automatic CDR backup mechanism.
The OMU conducts a regular CRC of the mainframe data. If the data of the mainframe is
not consistent with that of the background, the BAM server starts a setting procedure to
the foreground. If the setting procedure fails after preset attempts, an alarm is generated
to remind the operation staff to restore the data.
1.3 Datacom Solution
The proposed architecture of the datacom network is presented in this chapter. Two Core
Routers, Two Core LAN Switch, Three Firewall to be used in Dhaka. Brief description of the
network as stated below:
a) Core Routers
There will be two routers as Core Routers to be installed at Dhaka. These routers will be
connected each other by transmission resources (1GE) in the uplink and in downlink they are
connected with Core LAN Switch or Media Gateway directly.
b) Core LAN Switch
There will also be two LAN switches as Core LAN Switched to be installed at Dhaka. In
Dhaka site, these switches will be connected with Core Router for uplink and in the down link
they will connect with Media Gateway by multiple GE interfaces, Soft switch by multiple FE
interfaces. VRRP (Virtual Router Redundancy Protocol) is deployed between the connections
of all sites Core Router and Switches to implement the redundancy mechanism.
c) Firewall
There will be one firewall to protect the network elements and provide secure access or
connectivity for remote users. Firewall will be used between the network of NGN Switch
platform and Billing Center/NMS, BTRC and LEA.
Another 2 firewall will be deployed between Core Routers and Lanswitch to protect the
network elements from the International Attack.
Detail network diagram for BIG IGW IP Core Network is shown in the following Figure:
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Figure 5– IP Core Network Diagram
Equipment Place:
1. Core Router ( Dhaka)
2. Core LAN Switch ( Dhaka)
3. Firewall ( Dhaka)
Equipment List:
1. Core Router = NE40E (2Units)
2. Core LAN Switch = S9300 (2 Units)
3. Firewall = E1000E (1 Unit)
1.3.1 Bandwidth Capacity and Link Design
For voice service, the compression code of media compression arithmetic can adopt
different standards. Adopting different formats of message encapsulation, the formats and
efficiency of media message encapsulation in different packet bearer network (such as
Ethernet, IP, ATM) are different and should be determined by the actual bearer network.
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Compared with media traffic, the bandwidth of signaling traffic is very small. But it demands
higher for transmission reliability and low time delay.
Take the Dhaka Site as an example, according to the calculation of NGN core network
designing and planning table for all NGN and IP Equipment interface will be as below:
MGW – Core LAN Switch
Media traffic: GE optical link, load balancing mode
Soft Switch – Core LAN Switch
Signaling traffic: FE electrical link, active/standby mode
Core LAN Switch – Core Router
GE optical link
Core LAN Switch – Firewall
GE optical link
Firewall – BTRC, LEA, BILLING/NMS
FE electrical link
1.3.2 Datacom Solution Highlights
There will be five routers as Core Routers to be installed at four locations (Dhaka, Other 3
cities). These routers will be connected each other by transmission resources in the uplink
and in the downlink they are connect with Core LAN Switch via GE interface as well.
There will also be two switches as Core LAN Switch to be installed at Dhaka. These switches
will be connected with Core Router for uplink and in the down link they will connect with Media
Gateway by multiple GE interfaces, Soft switch by multiple FE interface.
Equipment Reliability
The hardware and software design greatly affect the reliability of the equipment. The Huawei
proposed NE40E routers adopt carrier class design and the availability of the system can
reach 99.999%. It has a passive backplane. All of the key parts such as main control board,
switching fabric, power supply and fan, have redundant design and are all hot swappable.
There is no single point of failure in the system. Besides, Huawei has implemented a large
number of reliability software features on the routers, including Non-Stop Forwarding,
Graceful Restart, Hot Patching and etc.
Network Reliability
To construct a high-reliable network, besides deploying high-reliable equipment, the
high-reliable characteristics of equipment should be effectively considered and applied in the
network layout to organize a high-reliable network with full redundancy capability.
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Service Access Reliability
Service access solution is also very important to ensure end to end service reliability.
Normally, the end service system (e.g. MGW or Softswitch) has dual connections to the
IP/MPLS network, and it has two working modes, one is active backup mode, another is load
sharing mode. For active backup mode, the end service system has one IP address for two
interfaces, for load sharing mode, the end service system has one IP address per interface.
To access service systems working in load sharing mode, we proposes that the end service
systems be directly connected layer 3 equipments so as to protect against the access link
failure.
Enhanced VRRP
Huawei core routers have enhancement on standard VRRP, which uses BFD for fast failure
detection and then trigger VRRP to switchover traffic. With enhanced VRRP, the switchover
time is reduced from more than 3 seconds to less than 50ms. Enhanced VRRP is used to
protect against local PE node failure and local PE-CE link failure.
1.4 Huawei Transmission Network Solution
1.4.1 Solution Overview
Huawei offers next generation SDH products OptiX OSN NG-SDH series OSN 3500, which can
provide SDH/PDH, Ethernet, ATM, and SAN service in a unified single platform. OSN 3500 is
STM-64/16 level equipment. In order to meet the ICX requirement for Transmission equipment,
Huawei offers OptiX OSN 3500 and OptiX iManager U2000 in this proposal.
Following equipments are offered as per requirement:
1. OptiX OSN Series Equipment
OptiX OSN 3500 1 Sets Dhaka
2. Dimension
Site STM-16 STM-4 STM-1 E1 FE
Dhaka-1 0 16 24
ICX will provide the connectivity between ICX and IGW. In ICX site, 2 OSN3500 will be deployed in
Dhaka Site to handle most of the transmission.
1.4.2 Huawei NG-SDH Features
Unified Platform
All the software and service cards, such as SDH, PDH, data cards (Ethernet, ATM, RPR, and SAN)
are universal to each other, which greatly minimize the initial investment, spare parts as well as
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maintenance cost. Network traffic upgradeability will be achieved just through modular expansion with
non-traffic affecting pattern, and without replacing the hardware system. Unified product series can
also shorten the time of network deployment and training expenses.
Data awareness Capability
As NG-SDH equipment, OptiX OSN 3500/1500 can provide abundant service interfaces for voice and
data services, such as SDH, PDH, ATM, FE/GE. For Ethernet data traffic Transport, it supports
GE/FE transparent transmission; convergence and L2 switch to address various customers'
requirements via GFP/LCAS/VCAT and supporting MPLS L2 VPN. It can also provide
ESCON/FICON/FC, ATM, WDM, RPR etc.
RPR (Resilient Packet Ring) Solution
The OptiX OSN series is integrated with RPR technology to support access, aggregate and transport
of 10M/100M/1000M Ethernet service. The main features and specifications are listed below.
Supports 10Base-T/100Base-FX/TX, 1000Base-SX/LX to access FE/GE Ethernet traffic
Supports encapsulation of GFP and LAPS protocols.
Supports VCAT (Virtual Concatenation) and LCAS mechanism for bandwidth protection of data traffic
Flexible configuration of the RPR ring from VC-3-1v to VC-4-8v. The mapping granule can be VC-3 or
VC-4.
Destination strip to realize spatial reuse mechanism
Bandwidth fairness Mechanism
Standard WRAPPING and STEERING protection mechanism with switch over time less than 50ms
and the optimized protection technology of WRAPPING+STEERING, which is Huawei patent
technology.
Auto recovery of the topology to plug and play.
Powerful QoS mechanism, support five priorities of A0, A1, B-EIR, B-CIR and C.
Supports MPLS and stack-VLAN technology to provide VPN in the RPR ring, the service can be
EVPL and EVPLAN.
Supports flow-control based on 64K granularity by the CAR (Committed Access Rate) scheme.
Ethernet over SDH Solution
The OptiX OSN series is integrated with Ethernet over SDH Technology to support access aggregate
and transport of10M/100M/1000M Ethernet service. The main features and specifications are listed as
below.
Supports 10Base-T/100Base-FX/TX, 1000Base-SX/LX to access FE/GE Ethernet traffic
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Supports Layer 2 switching and the ability to classify Ethernet traffic as defined in IEEE 802.1Q-tag
standard.
Mapping granularity: VC-12-nv, VC-3-nv, and VC-4-nv for Ethernet data, huge access and
transmission capacity up to 2.5Gbps per Ethernet service card.
Supports transparent transmission and convergence from FE to FE, FE to GE and GE to GE for
Ethernet traffic.
Supports Layer 2 VPN function and implements the EPL(Ethernet Private Line) , EVPL(Ethernet
Virtual Private Line), EPLn/EPLAN(Ethernet Private LAN) and EVPLn/EVPLAN(Ethernet Virtual
Private LAN) services.
Supports Link Capacity Adjustment Scheme (LCAS), achieving dynamic capacity adjustment of
transmission bandwidth and protection of concatenated group..
Support encapsulate protocols such as Generic Framing Procedure (GFP),High-level Data Link
Control (HDLC) and Link Access Procedure-SDH (LAPS).
High Traffic Grooming Capacity
It supports large capacity high/low order cross-connect, Multi-ADM design, and flexible add-dropping
capability. With high traffic grooming capacity, it supports STM-1/4/16/64 Mesh, ring, star and chain
topology.
Best for IP/ATM DSLAM Transport
The OSN series provides good transport solution for DSLAM. OSN support ATM solution, Ethernet
over SDH, RPR and WDM transport solutions for both ATM-based and IP-based DSLAMs. Different
solutions can be used for different requirements on bandwidth, and can be smoothly shifted from one
solution to another, so as to protect your investment.
Highly Integrated Platform
OSN series products support highly integrated large capacity traffic service boards with low power
consumption.
It also adopts OADM upgradeability just inserting new WDM cards on the existing platform without
replacing the hardware system. Therefore, NGSDH is the future-proof solution because these
features greatly preserve the original investment of your network.
Best for Lease line services
NG-SDH is the best for leased line services for business customers. So far, three different types of
leased line services are available over the OSN series products: the TDM leased line (transparent
transport mode), Ethernet private line (transparent transport mode) and Ethernet virtual private line
(Bandwidth is shared and VALN/LSP is used to isolate data of different users. Ethernet leased line
services can be very flexible in bandwidth, and can be either in the transparent mode or in the
bandwidth shared mode.
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Upgradeability (ASON -based platform)
OSN 3500/1500 are ASON-based platform, can be smoothly evolved into intelligent network just by
software upgrade. It supports intelligent features such as protection and restoration, Automatic
Topology and Resources discovery, automatic end to end service provisioning, SLA services etc.
Service provisioning in traditional SDH has been a manual, lengthy, and costly process. To manually
provision an end-to-end high-speed connection, a service provider must determine which SDH rings
the connection traverses and provision bandwidth on each ring manually. If any ring is at full capacity,
the carrier must find an alternative ring path or upgrade the capacity of a ring and propagate the
information to all sites manually. These are very time-consuming processes and can even take
months. The deployment of ASON–based nodes allows carriers to automate the provisioning and
management of the network and promises to lower the cost of operation by reducing service activation
times from few weeks to seconds via Point & click on EMS/NMS.
Several ASON-based networks which had been deployed by Huawei worldwide are in commercial
operation and these types of ASON-ready Huawei OSN series products has been deployed over 30
countries.
Operable & manageable Platform
Service boards are compatible to save spare part and operation cost, Hot-swappable SFP optical
modules, Remote board information collection and remote maintenance, In-service software upgrade,
IP over DCC, OSI over DCC for multi vendor interoperability and end to end service provisioning.
With highly integrated NP chips, full compatibility in hardware and software, special consideration for
Operation & maintenance, smoothly scalable to ASON networks (Automatic switching optical network),
OptiX OSN series will bring significant cost saving for BTCL in terms of CapEx and OpEx.
1.5 Power Solution
Huawei proposed power system covers stable, uninterrupted and efficient industry leading Rectifier
System, Battery Backup and Inverter System. TP481000D is a huge capacity AC&DC power system,
which convert AC to DC and supply -48V DC power to the telecommunication equipments in core
room. The TP481000D power system is usually composed of AC power distribution frames, DC
power distribution frames, rectifier frames, rectifier modules (SMR) and monitoring units (CSU).The
power system, using 48V/100A rectifier modules, can reach 6000A output by expansion. Huawei
proposed battery solution covers 8 hours backup comprising 2 sets of battery banks. Huawei
proposed inverter system is a high performance system suitable for the telecommunication
equipments which requires uninterrupted power solution. Our proposed Inverter System can be
monitored by LCD display for the proper monitoring and efficient usage.
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1.5.1 Dimension of Power Solution
The following table shows the power consumption requirement for Dhaka:
Product Quantity AC Power Requirement (W) DC Power Requirement (W)
Softx3000 1 334 1410.5
UMG8900 1 - 738
XPTU 1 250
SE2600 1 300 985
OSN3500 1 - 300
Total 634 3683.5
1.5.2 Reliability of Power Solution
For the reliability and uninterrupted DC power system, our proposed solution is based on the N+1
rectifier system design. The required rectifier system has been calculated based on the DC power
requirement for the load and battery charging current. Then the rectifier system has been provided as
N+1 redundancy.
For the reliability and uninterrupted AC power system, our proposed solution is based on the N+1
inverter system design. The required inverter system has been calculated based on the AC power
requirement for the load and the proposed inverter system has been provided as N+1 redundancy.
Besides, 8 hours battery backup has been provided comprising 2 sets of battery banks for the
uninterrupted Power Supply in case of the failure of commercial power. Sufficient CBs and fuses have
also been provided considering redundancy.
1.6 Huawei NMS Solution
Huawei O&M, iManager N2000 supports the monitoring and management of Softx3000 and
UMG8900 based on the same server. iManager N2000, which is the centralized element
management system (EMS) with centralized management functionalities on Huawei network
elements, including alarm management, performance management, configuration management,
software management, security management, etc. All these important functionalities equipped in
Huawei EMS as they are crucial for effective monitoring and management of BIG ICX. The detailed
O&M functionalities of the N2000 are illustrated in the diagram below.
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Figure 6 – N2000 O&M Functions
Operators can manage and maintain the authorized network elements via the N2000 Client, through
the TCP/IP Ethernet network. N2000 provides open and standard northbound interfaces to be
integrated into upper level NMS system. Huawei can therefore help the operator to build a highly
efficient and well-integrated O&M system. To monitor and manage the datacom and transmission
network, Huawei proposes U2000.
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Figure 7 – Inter-working of OSS and EMS
1.6.1 Powerful Huawei Network Management
iManager N2000 & U2000 can manage all the core network elements and the related IP network
equipments.
Characteristics:
Advanced modularized architecture
Abundant northbound interfaces for NMS integration
NE Software management and remote upgrade
Customized performance report based on Web
Alarm correlation
Delivering bulk MML commands to multiple NEs
Network time synchronization through NTP
High Availability system
Inventory information management
Full backup and restoration of N2000 & U2000
Equipment panel and interface tracing
Collection and storage of performance data
Centralized security management
Encrypted transmission in FTP mode based on SSL
Integrated script platform
Distributed system with multiple servers
Reliable and multiform security mechanism
1.6.2 Abundant Northbound Interfaces for OSS Integrated Solution
Huawei proposed NMS provides abundant and flexible northbound interfaces to the NMS. The
flexible northbound interfaces offered by the NMS can help operators to:
Conveniently and quickly construct the operation and maintenance system
Seamlessly integrate Huawei’s mobile NEs into their current O&M system
The integration proposal for configuration, monitoring, performance and backup is as follows:
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a) Configuration Tool Integration
Huawei proposed NMS provides configuration north-bound interface to the configuration tools for
inquiring the configuration files. It can export the configuration data into .xml files periodically.
The configuration tools can fetch the configuration files from the directory of the NMS through
FTP.
It supports configuration file importing interface that enables the configuration tools to modify
radio algorithm parameters and neighboring parameters. After updating the parameters, the
configuration tools transfer the configuration file to the NMS. It then parses the file and generates
script files and downloads them to NEs. Then the files are activated on NEs and NEs execute the
modification. When the execution completes, NEs generate result files and notify NMS. It then
collects the result files and combines them. The configuration tool can then get the result file from
the NMS through FTP. The detailed file format and control flow shall be negotiated and confirmed
by TMCZ and Huawei.
b) Monitoring Tool Integration
In Huawei OSS solution, our proposed NMS collects and stores all the alarms of all NEs. The
monitoring tool can collect the alarms from the NMS directly, instead of connecting to each NE. It
provides various alarm north-bound interfaces to the monitoring tools, including alarm ASCII
streaming interface, alarm CORBA interface, alarm file interface and alarm SNMP interface.
The NMS has successful stories of integration with HP TeMIP through alarm CORBA interface,
with IBM Micromuse Netcool through alarm ASCII streaming interface, alarm SNMP interface
and alarm COBRA interface.
c) Performance Tool Integration
In Huawei OSS solution, N2000 and U2000 collects and stores the performance data of all NEs.
The performance tool can collect the performance data from them directly instead of connecting
to each NEs. It provides the performance north-bound file interface to the performance tool.
It has successful stories of integration with IBM Vallent Metrica and Mycom NMS-Proptima
through performance north-bound file interface
d) Backup Tool Integration
Huawei proposed NMS supports to back up configuration data of the network elements and
system data of the NMS itself. The backup tool can get the backup files from the NMS through
FTP.
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1.7 Lawful Interception Solution
Huawei Softswitch solution supports LI solution and meets both ETSI and 3GPP specification. In
Huawei proposed solution, Huawei suggests MC (Monitoring Center) are purchased and managed by
national security administration or LEA. The following figure shows Huawei interception solution
logic architecture based on ETSI/3GPP.
Figure 5 – Lawful Interception Solution
Softswitch (Softx3000):
SOFTX3000 provides the support of LI function, and performs call control function for intercepted
calls. It can intercept all the communication and non-communication actions of the intercepted
number in real time. The communication actions include outgoing/incoming traffic,
supplementary service activation, SMS transmission/reception, FAX, etc. For the communication
action, Softswitch can generate and send IRI/CC to LIG/MC. For the non-communication actions,
Softswitch can generate and send IRI to LIG/MC. The LI service will not affect any other
telecommunication services.
MGW (UMG8900):
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The MGW is connected to the MC or LIG (modify according to your project) through E1s over
ISUP. It is controlled by the softswitch via H.248 protocol, to duplicate the interception content
(CC) and send to the MC or LIG through E1s in PCM voice format.
LIG:
LIG is Huawei internal terminology. In ETSI/3GPP standards, LIG is called “mediation”. Its main
functions are:
Managing the interception targets, the LI operator can use the LIG client to activate, list,
deactivate the interception targets. This function module is called ADMF in ETSI/3GPP
standards;
Receiving the interception related information from TNE and transferring it to MC. This
function module is called DF2 in ETSI/3GPP standards;
Optional: Receiving the interception call content from TNE and transferring it to MC. This
function module is called DF3 in ETSI/3GPP standards;
Controlling LIG system security and monitoring LIG system activity.
MC:
MC is Huawei internal terminology. In ETSI/3GPP standards, MC is called “LEMF”. Its main
functions are:
Receiving and Storing interception related information from LIG;
Receiving and Storing call content from LIG or TNE;
Intelligently analyzing the stored information, such like restoring the call content, intelligent
show the interception related information.
Interface and Function:
There are two kinds of interfaces in the LI solution: X interface and Handover interface (HI). X
interface is the interface between TNE and LIG, HI is the interface between LIG and MC.
X interface includes X1, X2, and X3 logical channels.
X1: based on TCP or UDP/IP, transmits the commands/responses between TNE and LIG.
LIG/MC can activate/deactivate/inquire targets through this channel. TNE is the server point
while X1 is based on TCP/IP protocol.
X2: based on TCP/IP, provides the interception relative information to LIG, like calls
establish/release PDP activation and so on. LIG is the server point in TCP link.
X3: transmits the Content of Communications, like speech, user packet.
Handover interface includes HI1, HI2, and HI3 logical channels.
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HI1:TCP/IP or manual. HI1 interface is the command control interface used to activate or
deactivate intercepted targets.
HI2: based on TCP/IP, MC will receive the IRI through this interface. LIG uses FTP protocol to
delivery IRI to MC according to ETSI/3GPP standards.
HI3: MC receives the intercepted CC (Call Content) through this interface.
1.8 Inter-working Solution
1.8.1 Inter-working with TDM Networks
Huawei has extensive experience in IOT execution and MVI (Multi-Vendor Integration)
deployment both in Huawei’s IOT open lab and in customer network environment. Huawei also
generated plenty of new software applications with our partners. Except the system integration
with our partners, Huawei also has performed the IOT of many standard interfaces with other
mainstream equipment vendors’ products.
Here IGW will connect with ICX or some of the International operators with TDM.
Softx3000 uses ISUP protocol to communicate with the TDM network in Signaling plane.
UMG8900 provides the inter-working functions with the TDM networks through SS7 signaling link,
also provides the necessary codec and media format translation functions. UMG8900 is
embedded with signaling gateway (SGW) function, support inter-working and adaptation from
MTP2, MTP3 to M2UA and M3UA. In this way, the UMG8900 acts as a single connection point to
TDM based networks and no independent SGW is needed. Various signaling protocols
supported by UMG8900 embedded SGW, such as R2, IUA, M2UA, M3UA and ISUP. Please
refer to the figure below for more illustration of the signaling protocol stack supported by
UMG8900.
Figure 8 – UMG8900 Protocol Stack
1.8.2 Inter-working with IP Networks
To inter-work with IP network, one SBC (SE2600) needs to be deployed at the IP network border
to control the voice, video, and data session.
It supports the following features:
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Network security
Quality of Service (QoS)
Network Address Translation (NAT)
While working as a I-SBC, SE2600 provides the following functions:
Serving as the SIP/SIP-T trunk and H.323 trunk, the SE2600 can interconnect the
SoftX3000s that are deployed in different networks.
By exchanging trunk signaling, the SE2600 allocates media addresses and port
numbers and generates channels for media streams to help forward media streams.
By handling signaling and media, the SE2600 supports NAT traversal, security defense,
and topology hiding.
Figure 9 - Inter-working with IP Network
1.9 Illegal Number Blocking
Since the VOIP number is illegal number in Bangladesh, Huawei provide the blocking illegal
number function in the expansion proposal. The number blocking function is provided by
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softswitch. BIG can configure any of the numbers or number ranges which need to be blocked in
the softswitch. When softswitch found the caller number is in the list of blocked number, the call
will be rejected by softswitch.
The function is incoming caller number discrimination; the number range to be rejected can be
configured in softswitch. When any incoming call go through BIG NGN, the softswitch would
compare the incoming call number with the configured illegal number, when the incoming call
number is the illegal number, the softswitch will reject the call directly.
1.9.1 The incoming call number is standard number.
Figure 11: Standard incoming call number
Subscriber B call subscriber A;
Softswitch will identify the B number with the number range which be configured as illegal;
The B number not included in the illegal number range;
The softswitch transfer the call to the A number normally.
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1.9.2 Illegal incoming number call rejected
Figure : illegal incoming call rejected
Subscriber B call subscriber A;
Softswitch will identify the B number with the number range which be configured as illegal;
The B number is included in the illegal number range;
The softswitch rejected the call.
2 Key Solution Highlights
1. High rate
The use of high-speed serial data links and the switching structure brings as wide as 2.5 Tbit/s
bandwidths for data switching.
2. High availability
All boards and back inserted boards are hot swappable, and a redundancy mechanism is
available for essential components such as power supply, fans, management modules, and
boards. This contributes to 99.999% system availability.
3. High expandability
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By adding an interface board to a subrack, the operator can increase the number of interfaces on
an board and realize subrack cascading.
4. High scalability
Backplanes can be smoothly upgraded to 10 GE, and the performance of the interface board is
highly scalable.
5. High manageability
The use of standard management buses realizes efficient management of any system
components.
The SOFTX3000 provides advanced hardware technology, featuring modular hardware structure,
large capacity, and high integration.
All boards use advanced integrated circuits such as the ASIC, PLD, and FPGA. This simplifies
the working of the SOFTX3000 and improves the integration of the system.
When serving as the Class-5 only, SOFTX3000 V300R010 supports a maximum of 2 million
subscribers. When serving as the Class4 only, SOFTX3000 V300R010 supports 360K TDM
trunk circuits.
With the distributed hardware structure, high-performance chips, high-speed buses, and high
speed Intel processors, the SOFTX3000 provides powerful processing capabilities.
Reliability
Huawei IGW solution and network elements are all designed to be fully redundancy. All the important
components, including Softx3000, UMG8900, OSN and NE40E are embedded with redundancy
features, including control cards, service processing cards, power supply, fans, bus and software
blocks, are designed to work in redundancy mode. There is no single point of failure in the whole
system. The H.248 connections between Softx3000 and UMG8900 are based on SCTP protocol and
Multi-homing mechanism is used to make it more reliable. SCTP with Multi-homing mechanism is also
been used in the SIGTRAN technology as transmission layer in both Softx3000 and UMG8900.
UMG8900 Protection Capability for TDM Connection
The UMG8900, as a large-capacity and high-density media gateway device, provides large-capacity
SDH/SONET interfaces. The SDH/SONET interfaces serve as the convergence interfaces of the
lower-layer network service, and its security is important. Therefore, the Huawei media gateway,
UMG8900 is designed with the function of SDH/SONET interface protection.
The SDH/SONET interface protection uses the linear multiplex section protection, and the protection
modes consist of the 1+1 backup and 1:N backup. When configuring the SDH/SONET interface
protection, set the optical interface on the master SDH/SONET interface board to the work channel of
the protection group, and that of the slave SDH/SONET interface board to the protection channel. In
this case, when the optical interface of the work channel fails, services are automatically switched to
the optical interface of the protection channel, and the services are not interrupted.
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The following figure shows the work mode of the 1+1 backup.
A B
Work channel
Protect channel
Work channel
Protect channel
Figure 20 – 1+1 Backup
In the 1+1 backup mode, each work channel has a dedicated protection channel. The transmitter
sends signals over the two channels, and the receiver receives the signals from the channel with the
signals of a better quality.
The following figure shows the work mode of the 1:N backup.
A B
Bridge Selector BridgeSelector
Protect channel (send)
Work channel 1 (send)
Protect channel (receive)
Work channel 1 (receive)
Work channel 2 (send)
Work channel 2 (receive)
Work channel N (send)
Work channel N (receive)
Figure 21 – N+1 Backup
The difference between the 1: N backup and 1+1 backup is that N channels share one dedicated
slave channel. When the system is normal, service streams are transmitted over the work channel.
When the work channel is disconnected or its performance deteriorates, the transmitter switches to
the protection channel to transmit the service streams and the receiver receives the information over
the protection channel.
IP Interface Load Sharing
The UMG8900 supports the load-sharing working mode of IP interfaces. Two load-sharing IP
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interfaces are configured with IP addresses respectively, and separately carry services. These two IP
interface are backup for each other. When a IP interface is faulty, traffic is automatically switched to
the other IP interface. Thus, the normal operating of bearer services is not interrupted.
Bidirectional Forwarding Detection
The UMG8900 supports the Bidirectional Forwarding Detection (BFD) protocol. Through BFD, the
UMG8900 periodically sends UDP-based fault detection packets, to detect and check disconnection
faults of the transmission link, optical interface, and electrical interface, and faults caused by
applications, such as packet loss, error code, and forwarding on the link layer and network layer.
When BFD deployed, the time of link changeover is below 200ms.
Excellent Voice Quality
Huawei IGW solution is embedded with different mechanism to guaranteed high quality of voice
in the network. In the VoIP networks, these factors can affect the voice quality from the following
aspects:
Delay and jitter
Delay and jitter refer to duration when an NE forwards service messages in a
communication network. When a voice packet is transmitted from A to B over the IP
network, time overhead is generated during the process of packet sending, transmitting,
and receiving. End-to-end delay contains codec delay, encapsulation and decapsulation
delay, and network transmission delay. Jitter is mainly caused by the network. The least
intermediate nodes (such as routers and switches) in the end-to-end transmission path
result in the smallest jitter. If a delay exceeds 250 ms, the communication satisfaction
decreases. Therefore, end-to-end delay cannot be longer than 250 ms.
Packet loss ratio
On IP networks, due to causes such as network congestion, service packets that cannot
be transmitted from the source address to the destination address are discarded. The
packet loss ratio is the percentage of lost packets in relating to the whole packets to be
transmitted. IP packets are lost on the IP network in two cases: The packets are lost
during the network transmission, and the routing device discards IP packets when the
network is congested. When the packet loss ratio is greater than 10%, the voice quality is
severely affected.
Echo
Echo indicates that speakers can hear their own voices in the earpiece during the
conversation. Echo is categorized into two types: electrical echo and acoustic echo.
Noise
Noise is any interfering sound, it can be thought of as any undesirable characteristic that
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degrades the signal of interest.
level
The voice level is an item used to measure the voice, and its unit is dBm. dBm represents
the decibels of one mW. The voice transmitting and receiving level is another key factor
affecting the voice quality. Therefore, the voice gateway must be able to adjust the voice
level. Usually, the voice level is set to 0 dBm.
Huawei Voice Quality solution
The UMG8900 realizes a series of voice technologies, including dynamic/static
Jitter-Buffer (DJB/SJB), electrical echo cancellation (EEC), acoustic echo cancellation
(AEC), gain control (GC), packet loss compensation (PLC), noise suppression (NS).
Huawei provide these VQE technologies to solve these problems
Figure 22– Voice Quality Solution
Factors Affecting Voice
Quality
Huawei VQE solution
Delay and jitter Dynamic and Static Jitter-Buffer
Packet loss ratio Packet Loss Compensation
Electrical echo Cancellation Electrical echo Cancellation
Acoustic echo Cancellation Acoustic echo Cancellation
Noise Noise Suppression
Level Automatic Gain Control
Dynamic and Static Jitter-Buffer
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Figure 23– Jitter-Buffer Processing
When voice streams are transmitted through the Nb interface across multiple MGWs on
an IP network, voice streams jitter occurs at the receiving end due to IP network jitter. To
minimize the impact of the IP network on the voice quality, the UMG8900 adopts the
Jitter-Buffer technology. That is, the UMG8900 buffers the received voice packets and
then outputs them at a regular interval after they re-queue. In this manner, jitter is
defeated and voices can be smoothly received. Please refer to the diagram above for
more illustration.
Generally, the longest Jitter-Buffer modifies the voice packet queue best, which, however,
results in long delay and degrades the voice quality. Therefore, the UMG8900 provides
the adaptive Jitter-Buffer technology to balance jitter and delay. That is, the UMG8900
can adjust the Jitter-Buffer depth against IP network jitter based on the actual jitter
conditions of an IP network.
Dynamic Jitter-Buffer: The DJB is automatically invoked by the system to improve the
voice quality for each VoIP call.
The UMG8900 also supports static Jitter-Buffer which is mainly applied to data services.
Users can set the SJB to 0–300 ms with the relevant command.
Packet Loss Compensation
Owing to network congestion, buffer overflow, and error bits, packages are always lost in
the connectionless network. Real-time data streams such as voice packets have a strict
sequence, and thus discarding is better than retransmission.
The voice compression codec algorithms used by IP calls are always in frame, and they
are sensitive to packet loss. Consecutive frame loss obviously affects the intelligibility,
naturalness, and clearness of the integrated voice at the receiving end. To avoid the
effect of packet loss, the package loss compensation (PLC) algorithm is used. Based on
the dependencies of the context voice information, the lost frames are regenerated during
the decoding, and in this way, the effect of the received voice is guaranteed.
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The PLC processing flow is shown in the following figure.
Figure 24 – Packet Loss Compensation Processing
Electrical Echo Cancellation
The echo means that the speaker voice is looped back to the speaker through network
devices. The feature of the echo is that the perceived quality of the speaker is affected,
and that of the hearer is not. In the single-IP telephone system, voice signals are received
and sent through different physical lines, that is, the four-wire circuits, and thus no echo is
generated. When the IP network and the PSTN network are interconnected, at least one
of the two communication parties is the two-wire phone, and two wire four wire
transformation circuits are covered, and the echo is generated.
The reason of the echo generation is as follows:
Full-duplex data transmission allows simultaneously transmitting messages in two
directions in one frequency band, that is, in a digital user loop, use one twisted pair cable
to transmit two signals of different directions. At the two full-duplex ends, the hybrid lines
are used to separate the transmission in two directions. To avoid the reflection of local
and remote signals at the hybrid, you must know the precise impedance of lines. The line
impedance depends on the line parameters; however, usually the precise line
parameters are unknown. In this way, attenuated and distorted transmission signals are
leaked to the input end of a receiver, and the echo arise. This is the electrical echo.
Automatic Gain Control
In the communications system, input voice signals are often collected with microphones.
When gains of the audio enlargement system are fixed, the collected voice signals vary
with the speaker’s distance to the microphone. In this way, remote users hear the voice
with unsteady volume, and the subject quality of voice decreases. To enhance the
subject quality of voice, the automatic gain control (AGC) technology is introduced. The
AGC function can compensate changes of the voice volume, retain the voice level, and
help users enjoy steady, clear conversations. At present, the voice quality enhancement
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(VQE) function provided by the UMG8900 has the following functions settings:
Enabling the AGC function or not as a whole.
Enabling the AGC function of the local exchange or other exchanges.
Setting the adjustment maximum value from 3 dB to 12 dB.
Setting the adjustment target level value.
Setting the target level from –23 dBm to –6 dBm.
Noise Suppression
At present, the voice quality enhancement (VQE) function provided by the UMG8900 can
support the noise suppression (NS) function. NS can:
Detect input signals during a conversation.
Identify and eliminate noise.
Provide clear, high-quality voice for users.
Enabling the noise reduction (NR) function or not according to the channel configuration.
The NR can:
Detect the local and remote input signals at the same time, or detect the local
or remote input signals, and identify and eliminate noise.
Set the noise suppression energy from 0 dB to 15 dB.
Automatically adjust the local or remote output voice volume based on the
local or remote input noise to help users in a noisy environment hear pleasant,
clear voice.
Enabling the noise compensation (NC) function or not according to the channel
configuration. The NC can:
Adjust the local and remote input signals, or adjust the local or remote input
signals.
Set the adjusted voice volume gains from 3 dB to 12 dB.
Voice quality specifications of UMG8900
In a good network condition: MOS > 4.0
In a poor network condition: MOS > 3.5
(packet loss rate = 1%, network jitter = 20 ms, delay = 100 ms)
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3 Annex A. Abbreviations and Acronyms
Abbreviation Description
ACL Access Control List
AMG Access Media Gateway
AS Application Server
ASL Analog Subscriber Line Board
ASN.1 Abstract Syntax Notation One
ATM Asynchronous Transfer Mode
BAM Back Administration Module
BAS Broadband Access Server
BGCF Breakout Gateway Control Function
BHCA Busy Hour Call Attempt
BRA Basic Rate Access
BFD Bi-directional Forwarding
BAM Back Administration Module
BHCA Busy Hour Call Attempt
CCF Charging Collection Function
CDB Central Database Board
CDR Charging Data Records
CLIP Caller Line Identification Presentation
CLIP Caller Line Identification Presentation
CMU Connection Maintenance Unit
CN Connection Node
CPU Central Processing Unit
CSCF Call Session Control Function
CDB Central Database Board
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Abbreviation Description
CLIP Caller Line Identification Presentation
DOPRA Distributed Object-oriented Programmable Real-time
Architecture
DCN Data Communication Network
DDI Direct-Dialing-In
DOPRA Distributed Object-oriented Programmable Real-time
Architecture
ECF Event Charging Function
ENIP Enhanced Network Intelligent Network
FRR Fast Reroute
FTAM File Transfer Access and Management Protocol
FTP File Transfer Protocol
FE Fast Ethernet
FTAM File Transfer Access and Management Protocol
FTP File Transfer Protocol
GE Gigabit Ethernet
GUI Graphical User Interface
H.248 H.248/MECAMGO protocol
HONET Home Optical Network
HRB High-speed Routing Board
HSS Home Subscriber Server
HTML Hyper Text Markup Language
IAD Integrated Access Device
IADMS Integrated Access Device Management System
I-CSCF Interrogating CSCF
ID Identity
iGWB iGateWay Bill
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Abbreviation Description
iMAP Integrated Management Application Platform
IMS IP Multimedia Subsystem
IM-SSF IP Multimedia Service Switching Function
INAP Intelligent Network Application Part
IP Internet Protocol
ISDN Integrated Services Digital Network
ISO International Organization for Standardization
ITU-T International Telecommunication Union -
Telecommunication Standardization Sector
ISDN Integrated Services Digital Network
L2UA Layer 2 User Adaption Layer
LAN Local Area Network
LDD Label Distribution protocol
LSP Label Switch Path
M3UA Message Transfer Part 3 (MTP3) -User Adaptation Layer
MA Multi-service Access
MCU Multipoint Control Unit
MDC Message Distribution Center
MG Media Gateway
MGCF Media Gateway controller Function
MGCP Media Gateway Control Protocol
MGW Media Gateway
MIB Management Information Base
MML Man Machine Language
MRF Media Resource Function
MRFC Media Resource Function Controller
MRFP Media Resource Function Processor
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Abbreviation Description
MRS Media Resource Server
MTBF Mean Time Between Failure
MTP Message Transfer Part
MTTR Mean Time To Repair
NAT Network Address Translation
NGN Next Generation Network
NMS Network Management System
NIC Network Interface Card
NMS Network Management System
NPB Network Processing Board
OLT Optical Line Terminal
ONU Optical Network Unit
OSA Open Service Access
OSS Operating Support System
POTS Plain Old Telephone Service
PSTN Public Switched Telephone Network
PBX Private Branch Exchange
PC Personal Computer
P-CSCF Proxy CSCF
PDH Plesiochronous Digital Hierarchy
PLMN Public Land Mobile Network
POTS Plain Old Telephone Service
PRA Primary Rate Access
PSTN Public Switched Telephone Network
PVM Packet Voice Module
QoS Quality Of Service
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Abbreviation Description
RAID Redundant Array of Inexpensive Disks
RM Resource Manager
RPB Resource Processing Board
RPR Ring Packet Resilience
RTP Real-time Transport Protocol
SCF Session Charging Function
S-CSCF Serving CSCF
SDH Synchronous Digital Hierarchy
SG Signaling Gateway
SGW Signaling Gateway
SHLR Smart Home Location Register
SIP Session Initiated Protocol
SMB System Management Board
SNMP Simple Network Management Protocol
SPB Service Processing Board
SQL Structured Query Language
STM-1 Synchronous Transfer Mode 1
SYS System Management Board
STM-1 Synchronous Transfer Mode 1
TDM Time Division Multiplexing
TCP Transmission Control Protocol
TFTP Trivial File Transfer Protocol
TL1 Transaction Language 1
TMG Trunk Media Gateway
TMN Telecommunications Management Network
TSS Test Board
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Abbreviation Description
UMS U-SYS Management System
UDP User Datagram Protocol
UMG Universal Media Gateway
URL Uniform Resource Locator
VoIP Voice Over IP
VPN Virtual Private Network
VoIP Voice Over IP
VPN Virtual Private Network
VSP Voice-band Signal Processing Board
VSU Voice-band Signal Unit
VVR Veritas Volume Replication
WAN Wide Area Network
XML Extensible Mark-up Language